In the beginning, Massachusetts opened the gates to same-sex marriage and universal health coverage. California started to liberalize drug laws by legalizing medical marijuana. The sky didn’t fall on any of these efforts, initially regarded as dangerous social experiments by many conservatives.

Now red states such as Kentucky are launching state-run health insurance exchanges. Federal judges in conservative Utah and Oklahoma are calling bans on gay marriage unconstitutional. And purple Colorado has legalized recreational marijuana use.

Most of us have a vision of the way things ought to be. It is human nature to want others to see the same light we do.

Conservative foes of abortion hold deep convictions that ending a pregnancy is a moral travesty. Liberals make similar arguments against a health care system that lets thousands of Americans die for lack of medical attention, which happens when market forces run the show.

Social activists who live and breathe their cause often seek to impose their views on a diverse nation. They don’t realize that they can more easily get what they want in states whose culture shares their views. Showing that a state has enacted their ideas with good effect is the most expedient way of spreading their ideas coast to coast. But putting such power in state hands doesn’t always sit well. Liberals, especially, point to slavery and Jim Crow laws as great evils that flew under the banner of states’ rights. These were moral outrages that the federal government had to stop, and did. True, but many less momentous struggles can be more peaceably and efficiently won through example. As the late U.S. Supreme Court Justice Louis Brandeis famously said, states can serve as the “laboratories of democracy.” Many liberals are enthusing over a bill introduced last month by Sen. Bernie Sanders, a liberal Vermont independent, and Rep. Jim McDermott, a Washington state Democrat, which would create a national single-payer health care system.

I happen to think the Sanders-McDermott proposal — actually a modified single-payer plan allowing private supplemental coverage — is splendid. But it also has zero chance of passage. Recall how even the modest “public option” — a government plan to compete with the private insurers — couldn’t get past Congress, including some Democratic members.

The best hope for national single-payer is to let Vermont show that its homegrown version will work. If Vermont can cut its health care spending by over 30 percent under single-payer, as is projected, other states will copy it, with no pressure needed from Washington. Gay activists regard laws banning same-sex marriage as a great injustice, and with reason. But simply waiting for a Supreme Court decision making same-sex marriage legal nationwide, no certainty, would have been a massive waste of time. Marriage is a state responsibility, so what better place to change the laws than in states open to it? New Mexico’s Supreme Court just ruled that the ban on gay marriage was unconstitutional. In Virginia, another purple state, the Democratic leaders are going full speed ahead. They are bolstered by polls showing that 56 percent of Virginians are in favor of same-sex marriage, a reversal from the 57 percent supporting a ban in 2006. This tide of change would not have rolled in had liberal states not demonstrated what happens to the broader society when gay couples marry — very little.

Some states will do things noxious to liberals, for example, on gun control and public financing for education. Conservatives will dislike decisions made in liberal places. Fine. Let’s all make a pact to stop trying to make everyone else over in our own image.

Nothing convinces like successful examples. Liberals, above all, should have more confidence in their own.

Follow Froma Harrop on Twitter @FromaHarrop. She can be reached at fharrop@gmail.com. To find out more about Froma Harrop and read features by other Creators writers and cartoonists, visit the Creators Web page at www.creators.com.